Wave propagation in one-dimensional fluid-saturated porous phononic crystals with partial-open pore interfaces

Significance 

Phonic crystals (PCs) are a class of artificial periodic composites that have drawn significant research attention owing to their potential application in controlling acoustic wave propagation. Besides possessing bandgaps and strong dispersion, PCs also exhibit a range of peculiar properties that makes them attractive for various applications. Generally, they compose of materials with interfaces between them. The presence of the interfaces between similar or different material phases has resulted in an extensive study of the effects of interfaces boundary on wave propagation in phonic crystals. However, most existing studies focus on single-phase media and not multi-phases phononic crystals. In addition, the scattering of waves is a common phenomenon between porous media interfaces and has also been extensively studied in the literature. For instance, previous findings revealed the possibility of generating slow longitudinal waves at the interface between different media, considering the effects of the fluid transfer at the interface. Other studies have also investigated the transmission and reflection of elastic waves, the propagation of elastic and seismic waves through the dislocation-like interface, and the influence of boundary conditions on the energy partition.

Nevertheless, despite the remarkable progress, more research is still needed to thoroughly understand the propagation of different waves across phonic crystals and the effects of the resulting boundary conditions. For fluid-saturated porous periodic structures, wave propagation is mainly affected by the interface between the adjacent layers. Equipped with this knowledge, Beijing Jiaotong University researchers: Shu-Yan Zhang (PhD candidate), Dr. Dong-Jia Yan and Professor Yue-Sheng Wang in collaboration with Dr. Yan-Feng Wang from Tianjin University and Professor Vincent Laude from Institut FEMTO-ST investigated the wave propagation in one-dimensional (1D) fluid-saturated porous PCs with partial-open pore interfaces. The work is currently published in the International Journal of Mechanical Sciences.

In their approach, the authors considered poroelastic waves propagation in 1D fluid-saturated porous PCs with varying interface conditions. The poroelastic Bloch waves and complex band structures of the crystals were obtained via a transfer matrix method. Consequently, a stiffness matrix method was used to determine the spectral transmission through the finite structures. Lastly, the influence of the material parameters (porosity, viscosity and pore blockage coefficient) and the pore blockage were investigated. It is important to note that the study was restricted to the normal incidence of the investigated longitudinal waves.

Results showed that the wave propagation was strongly influenced by the porosity, viscosity and pore blockage coefficient. This was more pronounced for the avoided crossings amongst the slow and fast longitudinal waves. Additionally, the pore blockage value was observed to significantly influence both the partition of the wave energy between the solid skeleton and pore fluid and poroelastic wave dispersion. Furthermore, the effects of the viscosity and porosity were found to be similar for both partial-open and fully open-pore interface conditions.

In summary, the study investigated the propagation of waves in 1D fluid-saturated porous PCs with partial-open pore interfaces. Both stiffness and transfer matrix methods were devised and used to calculate the transmission spectra and complex band structures, respectively. A good agreement between the obtained results and that of the previously reported finite element results was reported. Based on the results, the approach was versatile and could be applied to both 2D and 3D scenarios with the consideration of additional interfaces and waves. In a statement to Advances in Engineering, the authors said their new findings will expand the practical applications of phononic crystals.

Reference

Zhang, S., Yan, D., Wang, Y., Wang, Y., & Laude, V. (2021). Wave propagation in one-dimensional fluid-saturated porous phononic crystals with partial-open pore interfacesInternational Journal of Mechanical Sciences, 195, 106227.

Go To International Journal of Mechanical Sciences

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